COMPRESS considers external flange loads by converting them to an equivalent pressure and superimposing this equivalent pressure on the design pressure. The equivalent pressure due to radial loads (axial to flange) and bending moments is found using the method described in Dennis R. Moss' "Pressure Vessel Design Manual, Second Edition" Appendix G, p. 273. This is the same method described in ASME Code Section III, Division 1, NC-3658.1, as referenced in COMPRESS. The various terms used by COMPRESS are defined as follows:

"P_s" refers to the static head (pressure) acting on the flange due to the weight of operating liquid.

"P_m" refers to the bending moment acting on the face of the flange. User defined bending moments or bending moments calculated by COMPRESS (due to eccentric loads and wind or seismic loads) are used to determine P_m.

"P_r" refers to the radial (axial) load on the flange acting on the flange face due to external loads. These external loads, typically resulting from the weight of the vessel supported by the flange, include user defined weights and weights calculated by COMPRESS.